410 * 
PALAEONTOLOGY OF NEW-YORK. 
PLATE LXXXI B. 
Fig. 1. A specimen of medium size, lying with the dorsal side exposed. The carapace has 
been broken off, showing the inner side of the maxillary plates, the post-oral 
plate, and the four anterior pairs of feet, which are obscured at their bases. The 
body is curved, and the tail-spine directed forwards. The pustuliform scales upon 
the back are in four rows on the thoracic joints, and two slightly diverging rows 
on the abdominal joints. 
Fig. 2. The last joint of the swimming foot, with the minute palette at the extremity. 
Fig. 3. The seventh joint of the swimming foot, having the triangular chelate extension 
separated at the suture. 
Fig. 4. The first articulation of the ventral side, with the organs attached. 
Fig. 5. A portion of the surface enlarged, showing the scale-like markings. 
PLATE LXXXIII B. 
Fig. 3. The carapace of a large individual, showing the form to be distinct from fig. 2, which 
is the carapace of E. remipes. 
Geological position and locality. In the Waterlime group : Near Williamsville, 
and near Buffalo, Erie county, New-York. 
Euryptems lacustris, var. mbustus. 
Plate LXXXI C. Fig. 1. 
Carapace comparatively small. Body very robust, elongato-ovate. Joints 
of the thorax broad and strong, their width being from four to six times 
their length. Caudal segments increasing rapidly in length : terminal 
spine unknown. The central locomotive appendage of the first joint of 
the thorax is obsolete or imperfectly developed. The three anterior pairs 
of feet strong and short-jointed, the first pair reaching little beyond 
the margin of the carapace ; the fourth pair extending far beyond the 
carapace : joints long, and thickened at the distal extremity ; postoral 
plate oval-ovate, broader anteriorly and slightly emarginate in front; 
maxillary plates broad, rhomboidal. The second and third joints are 
obscured ; the fourth, fifth and sixth are well preserved, and show the 
prolongation of the anterior edges in short spine-like processes over the 
<• 
next joint, which, exclusive of the soldered piece, is little longer than 
wide : the eighth joint is oval-ovate, about twice as long as wide, 
bilobed at the tip for the reception of the terminal palette, which is 
small and scarcely exsert. 
